Seam for woven paper making fabrics

ABSTRACT

A seam for joining opposite ends of a woven fabric to form a loop or belt suitable for various uses in connection with paper making machines. The seam is formed by using weft strands from the woven fabric for seam wefts. Weft strands on each end of the woven fabric are removed to leave warp pickets which are then interwoven with the seam wefts to form the seam, whereby the pattern of the weave across the seam is the same as that in the body of the fabric. The ends of successive warp strands are terminated over different seam wefts in a pattern which includes at least a six-warp sequence. The ends of adjacent warp strands terminate in spaced rows of seam wefts in a repeated sequence with a plurality of seam wefts between adjacent rows. The spacing and direction of the respective warp terminations are such as to achieve suitable seam strength and a reduced tendency to mark the paper sheet formed on the belt.

United States Patent [191 Hill, Jr. et a1.

[ SEAM FOR WOVEN PAPER MAKING FABRICS [75] Inventors: Vernon J. Hill,Jr., Chagrin Falls;

Earl A. Southam, Cleveland Heights, both of Ohio; John R. McDowell,Knoxville, Tenn.

[73] Assignee: The Lindsay Wire Weaving Company, Cleveland, Ohio [22]Filed: Jan. 19, 1972 [21] Appl. N0.: 219,050

[451 Jan. 8, 1974 Primary Examiner Richard .1. l-lerbst Att0rneyTeare,Teare & Sammon [5 7 ABSTRACT A seam for joining opposite ends of a wovenfabric to form a loop or belt suitable for various uses in connectionwith paper making machines. The seam is formed by using weft strandsfrom the woven fabric for seam wefts. Weft strands on each end of thewoven fabric are removed to leave warp pickets which are then interwovenwith the seam wefts to form the seam, whereby the pattern of the weaveacross the seam is the same as that in the body of the fabric. The endsof successive warp strands are terminated over different seam wefts in apattern which includes at least a sixwarp sequence. The ends of adjacentwarp strands terminate in spaced rows of seam wefts in a repeatedsequence with a plurality of seam wefts between adjacent rows. Thespacing and direction of the respective warp terminations are such as toachieve suitable seam strength and a reduced tendency to mark the papersheet formed on the belt.

2 Claims, 4 Drawing Figures PATENTED JAN 74 BACKGROUND OF THEINVENTION 1. Field This invention relates to a seam for fabric woven ofmetal or plastic warps and wefts or a combination of the two in whichthe warps terminate along a band of seam wefts in a predeterminedpattern.

2. Desription of the Prior Art Fabrics used for paper making such as thepaper forming belt on a Fourdrinier machine, or covers on press rolls ofa paper making machine, are often woven as a length of fabric with metaland/or plastic warps and wefts and the opposite ends of the fabric arethen joined along a seam to form an endless belt or loop. Various formsof seams have been illustrated in US. Pats. No. 3,366,355 and No.3,552,691. The making of a seam by butt-welding the warp ends or byadhesively connecting the warp ends has not been found to developadequate strength and tend to mark the paper sheet produced. Othermethods, such as sewing or lacing are disadvantageous in that anirregularity is usually formed in the belt, as a consequence of whichobjectionable irregularities occur in the resulting paper sheet.

SUMMARY OF THE INVENTION The present invention relates to an improvementin a seam construction by utilizing at least a six-warp sequence in arepeated pattern wherein all of the corresponding warp ends of asequence terminate at a common seam weft. Thus, the seam has spaced rowswherein all of the warp ends on a first warp of each sequence terminateon a common row adjacent one edge of the seam, and all of the warp endson the sixth warp of each sequence terminate on a common row adjacentthe opposite edge of the seam. The intervening warp ends are spaced inrows lying between the first and sixth rows and such rows are so relatedto the warp ends of the sequence, that the distance between the warpends on any two adjacent warp strands comprises at least two of the rowsthroughout the sequence, with the additional provision that the warpends on the intermediate strands terminate in rows which are located ina prearranged direction with respect to the first and last rowsrespectively. Such arrangement results in the attainment of a seam whichhas a high tensile strength.

An object of the present invention is to provide a new seam constructionfor use in woven metal or plastic fabrics, as employed in paper makingwhich utilizes at least a six-warp pattern, wherein the warp ends of therespective warp strands in a sequence are so positioned with referenceto each other, that maximum resistance to distortion during use will beattained.

A further object of the invention is that if distortion or warp-end wearshould occur, the relative location of the warp ends is such as tominimize the detrimental effeet on the performance of the seam and belt.

DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates in perspective view aFourdrinier belt formed of woven fabric and illustrates the belt asbeing mounted upon supporting rolls on the paper making machine;

FIG. 2 is a longitudinal sectional view on an enlarged scale showing aportion ofthe belt adjacent the seam;

FIG. 3 illustrates an embodiment of the seam construction of the presentinvention in a six-warp pattern; and

FIG. 4 illustrates an embodiment of the seam construction of the presentinvention and shows a seam utilizing an eight-warp pattern.

DESCRIPTION OF PREFERRED EMBODIMENT FIG. 1 illustrates typical use of aseam construction embodying the present invention. It shows an endlessbelt as may be used as the paper making surface on a Fourdriniermachine. The belt is formed from a length of woven fabric having itsopposite ends joined along a seam l1, and is shown as being mounted uponrolls 12 and 13, respectively, the latter of which may comprise thedriving roll. The arrows 14 and 15 indicate the direction of movement ofthe upper and lower reaches respectively of the belt while in operationon a machine.

The body of the fabric comprises warp strands which extend in thedirection of the arrow 14 in FIG. 1, which are interwoven with weftstrands which extend transversely of the belt and at a right angle tothe direction of the arrow 14. The fabric is woven so as to have alength greater than that required for the finished belt.

Subsequent processing may occur. For example, in the case of an allplastic belt, it may be stretched and heat-set so as to control theshape of the warp and weft knuckle configuration and to impart desirablecharacteristics to the finished product.

Prior to making the seam described herein, the belt is trimmed to adesired length which is greater than the length it will be afterseaming. Woven wefts are removed from each end of the belt for a desireddistance to provide warp end extensions necessary to the construction ofthe article claimed. These warp extensions are termed pickets. Elementsthat are woven wefts in the belt become seam wefts in the constructionof the article claimed.

The seam wefts are then placed between the ends of the fabric and theopposing warp pickets are interwoven with the seam wefts so as tomaintain the same pattern of weave across the seam as that which existedin the body of the fabric. During such weaving operation the opposingwarp ends are brought out within the seam area adjacent the same seamweft and the excess portion of each warp picket is cut off. As shown,for example, in FIG. 2, the warp pickets 18 and 19 on opposite ends ofthe same warp strand are terminated at 20 and 21, respectively, adjacentthe same seam weft 22.

FIG. 3 shows, on an enlarged scale, the seam area 16 after the seamwefts have been interwoven with the warp pickets. In such illustrationthe seam wefts extend from left to right and the warp strands extendfrom top to bottom. The various rows of seam wefts, adjacent which thewarp ends of the respective warp strands are terminated, are indicatedat A to F, respectively, wherein an X at the junction of the warpstrands with the seam wefts indicate the locations at which the warpends of the respective warp strands are located with reference to eachother.

In FIG. 3, the upper edge of the seam is in the region designated andthe lower edge of the seam is in the region designated 26. Commencingwith the first warp strand 30, the warp ends terminate on row A at afterthe pickets have been interwoven with the seam wefts, as shown in FIG.2. Similarly, the warp ends for the second warp strand 31 are indicatedat 41 on row C. The

pattern in FIG. 3 is shown as a six-warp pattern, hence the warp-endterminations for the third warp strand 32 occur at 42 on row E; the warpends for the fourth warp strand 33 occur at 43 on row B; the warp endsfor the fifth warp strand 34 occur at 44 on row D, while the warp endsfor the sixth warp strand 35 occur at 45 on row F. The pattern is thenrepeated so that the warp ends for the first warp strand 36 on thesecond pattern terminate at row A and are indicated at 46.

The foregoing seam pattern shows that the location of the warp ends forthe second warp strand 31 skip the row B and are at row C. Similarly,the location of the warp ends for the warp strand 32 skip row D and areat row E. Such rows are positioned in the direction toward row F withrespect to row A. The direction is then changed so that the location ofthe warp ends for In the foregoing arrangement there are five warpstrands between any two warp end terminations on the samerow.Additionally, the spacing in a warp-wise direction on adjacent warpstrands is at least two rows. In practice, assuming that about 60 seamwefts extend between rows A and F, then by spacing the rows A to F asnearly equal as possible, there will be at least 23 or 2 4 seam weftsbetween the warp termination on adjacent warp strands. The net resultsof the arrangement is that the load on the seam during use isdistributed more uniformly over the same area.

The present invention is applicable for various forms of weave patterns,that illustrated in FIG. 2 being a semi-twill weave where the warpstrand passes over one weft strand and then under two in succession. Theinvention is also applicable for use in what is termed in the art as afour-harness satin weave, as is illustrated, for example, in FIG. 4,wherein the pattern extends across eight-warp strands and has the warpends terminating in eight rows. In such figure, the rows are indicatedas .I to respectively, while the beginning of a new pattern would occuron warp strand 58. Additionally, in FIG. 4, the warp end terminationsoccur progressively on row 1, L, N, P, K, M, O and Q. As the pattern isrepeated, the warp ends for warp strand 58 terminate at row J so thatseven-warp strands lie between adjacent warp terminations on the samerow. As shown in FIG. 4, the seam may have about 80 seam wefts, andagain the spacing between rows of seam wefts should be as nearly equalas possible. In this arrangement, the location of warp ends again skipat least one row and extend generally in the direction of the row 0 forfor the second, third and fourth warp strands, then back to row K in thedirection of the first row and then back toward the row Q for theremaining three warp terminations.

The foregoing seam construction enables the weave pattern in the body ofthe fabric to be continued across the seam and at the same time enablesa seam to be made which will provide adequate strength and reduced seammarking tendency for fabrics which are woven of synthetic material, suchas nylon or Trevira. The seam is also suitable for use where some of thestrands are made of metal and others in the same fabric are made ofsynthetic materials.

it has been woven and which have been interwoven with warp-endsprojecting from each end of the fabric so as to maintain across the seamthe same weave pattern as that of the woven fabric,

said seam having a first edge portion adjacent one end of the fabric andhaving a second edge portion adjacent the other end of the fabric,

said warp-ends being arranged in a six-warp sequence wherein the ends ofthe adjacent warp strands terminate in spaced rows of seam-weftsdesignated as first to sixth row respectively, in a repeated sequence,and there being a plurality of seam-wefts between adjacent rows,

both of the warp ends of the first warp strand in each sequenceterminating in the first row adjacent one edge portion of the seam,

both of the warp ends of the last warp strand in each sequenceterminating in the sixth row adjacent the other edge portion of theseam,

all of the intermediate warp ends in each sequence terminating in rowstwo to five,

the distance between the warp ends on adjacent warp strands comprisingat least two of said rows throughout the sequence,

the spacing of the warp ends on adjacent warp strands progressivelythroughout the sequence being as follows:

the warp ends on the second warp strand are spaced two rows from saidfirst row and in the direction of the sixth row,

the warp ends on the third warp strand are spaced two rows from the warpends on the second warp strand and in the direction of the sixth row,

the warp ends on the fourth warp strand are spaced three rows from thewarp ends on the third warp strand and in the direction of the firstrow,

the warp ends on the fifth warp strand are spaced two rows from the warpends on the fourth warp strand and in the direction of the sixth row,and

the warp ends on the sixth warp strand are spaced two rows from the warpends on the fifth warp strand and in the direction of the sixth row.

2. In a length of woven fabric having its ends joined by a seam to forma loop, said length of fabric comprising spaced warps interwoven withspaced wefts (hereinafter referred to as woven-wefts) in a selectedrepeated pattern and said woven-wefts being crimped during the weavingof the fabric to have knuckles in which fabric the warps and woven-weftsare metal or plastic, the combination wherein:

the seam comprises a plurality of seam-wefts which have been removedfrom the length of fabric after it has been woven, and which have beeninterwoven with warp ends projecting from each end of the fabric, so asto maintain across the seam the same weave pattern as that of the wovenfabric,

said seam having a first edge portion adjacent one end of the fabric andhaving a second edge portion adjacent the other end of the fabric,

said warp ends being arranged in an eight-warp sequence wherein the endsof the adjacent warp strands terminate in spaced rows of seam-weftsdesignated as first to eighth row respectively in a repeated sequence,and there being a plurality of seam wefts between adjacent rows,

both of the warp ends on the first warp strand in each sequenceterminating in the first row adjacent one edge portion of the seam,

both of the warp ends on the last warp strand in each sequenceterminating in the eighth row adjacent the other edge portion of theseam,

all of the intermediate warp ends in each sequence terminating in rowstwo to seven,

the distance between the warp ends on adjacent warp strands comprisingat least two of said rows throughout the sequence,

and the spacing of the warp ends on adjacent warp strands progressivelythroughout the sequence being as follows:

the warp ends on the second warp strand are spaced two rows from saidfirst row and in the direction of the eighth row,

the warp ends on the third warp strand are spaced two rows from the warpends on the second warp strand and in the direction of the eighth row,

the warp ends on the fourth warp strand are spaced two rows from thewarp ends on the third warp strand and in the direction of the eighthrow,

the warp ends on the fifth warp strand are spaced five rows from thewarp ends on the fourth warp strand and in the direction of the firstrow,

the warp ends on the sixth warp strand are spaced two rows from the warpends on the fifth warp strand and in the direction of the eighth row,

the warp ends on the seventh warp strand are spaced two rows from thewarp ends on the sixth warp strand and in the direction of the eighthrow, and

the warp ends on the eighth warp strand are spaced two rows from thewarp ends on the seventh warp strand and in the direction of the eighthrow.

1. In a length of woven fabric having its ends joined by a seam to forma loop, said length of fabric comprising spaced warp strands interwovenwith spaced weft strands (hereinafter referred to as woven-wefts) in aselected repeated pattern and said woven wefts being crimped during theweaving of the fabric to have knuckles, in which fabric the warps andwoven-Wefts are metal or plastic, the combination wherein: the seamcomprises a plurality of seam-wefts which have been removed from thelength of fabric after it has been woven and which have been interwovenwith warp-ends projecting from each end of the fabric so as to maintainacross the seam the same weave pattern as that of the woven fabric, saidseam having a first edge portion adjacent one end of the fabric andhaving a second edge portion adjacent the other end of the fabric, saidwarp-ends being arranged in a six-warp sequence wherein the ends of theadjacent warp strands terminate in spaced rows of seam-wefts designatedas first to sixth row respectively, in a repeated sequence, and therebeing a plurality of seam-wefts between adjacent rows, both of the warpends of the first warp strand in each sequence terminating in the firstrow adjacent one edge portion of the seam, both of the warp ends of thelast warp strand in each sequence terminating in the sixth row adjacentthe other edge portion of the seam, all of the intermediate warp ends ineach sequence terminating in rows two to five, the distance between thewarp ends on adjacent warp strands comprising at least two of said rowsthroughout the sequence, the spacing of the warp ends on adjacent warpstrands progressively throughout the sequence being as follows: the warpends on the second warp strand are spaced two rows from said first rowand in the direction of the sixth row, the warp ends on the third warpstrand are spaced two rows from the warp ends on the second warp strandand in the direction of the sixth row, the warp ends on the fourth warpstrand are spaced three rows from the warp ends on the third warp strandand in the direction of the first row, the warp ends on the fifth warpstrand are spaced two rows from the warp ends on the fourth warp strandand in the direction of the sixth row, and the warp ends on the sixthwarp strand are spaced two rows from the warp ends on the fifth warpstrand and in the direction of the sixth row.
 2. In a length of wovenfabric having its ends joined by a seam to form a loop, said length offabric comprising spaced warps interwoven with spaced wefts (hereinafterreferred to as woven-wefts) in a selected repeated pattern and saidwoven-wefts being crimped during the weaving of the fabric to haveknuckles in which fabric the warps and woven-wefts are metal or plastic,the combination wherein: the seam comprises a plurality of seam-weftswhich have been removed from the length of fabric after it has beenwoven, and which have been interwoven with warp ends projecting fromeach end of the fabric, so as to maintain across the seam the same weavepattern as that of the woven fabric, said seam having a first edgeportion adjacent one end of the fabric and having a second edge portionadjacent the other end of the fabric, said warp ends being arranged inan eight-warp sequence wherein the ends of the adjacent warp strandsterminate in spaced rows of seam-wefts designated as first to eighth rowrespectively in a repeated sequence, and there being a plurality of seamwefts between adjacent rows, both of the warp ends on the first warpstrand in each sequence terminating in the first row adjacent one edgeportion of the seam, both of the warp ends on the last warp strand ineach sequence terminating in the eighth row adjacent the other edgeportion of the seam, all of the intermediate warp ends in each sequenceterminating in rows two to seven, the distance between the warp ends onadjacent warp strands comprising at least two of said rows throughoutthe sequence, and the spacing of the warp ends on adjacent warp strandsprogressively throughout the sequence being as follows: the warp ends onthe second warp strand are spaced two rows from said first row and inthe direction of the eighth row, the warp ends on the third warp strandare spaced two rows from the Warp ends on the second warp strand and inthe direction of the eighth row, the warp ends on the fourth warp strandare spaced two rows from the warp ends on the third warp strand and inthe direction of the eighth row, the warp ends on the fifth warp strandare spaced five rows from the warp ends on the fourth warp strand and inthe direction of the first row, the warp ends on the sixth warp strandare spaced two rows from the warp ends on the fifth warp strand and inthe direction of the eighth row, the warp ends on the seventh warpstrand are spaced two rows from the warp ends on the sixth warp strandand in the direction of the eighth row, and the warp ends on the eighthwarp strand are spaced two rows from the warp ends on the seventh warpstrand and in the direction of the eighth row.